In the beginning…
Every time I take a long Falci grass blade out into the paddock, I expect to have to do a bit of fine tuning to hit the blade’s ‘sweet spot’ where it mows best.
This is partly because of the first tests I did with a Falci vs. Fux blade, which are indelibly seared into my memory.
I took my 75cm Fux blade out onto the lawn, along with a new 75cm Falci blade, and two matching Swiss snaths (the Canadian ones weren’t ready at the time).
The Falci absolutely killed the Fux, hands downs, no competition – it mowed better (see the pic that I took at the time), more easily, and felt nicer in the hands, being a lighter blade.
Then I took the same two rigs out into the paddock and my world nearly fell apart… the Fux killed the Falci. Over the next few days Tony and I spent literally hours figuring out how the Falci could outperform the Fux so convincingly on the lawn, and then fail so convincingly in the paddock.
The first problem was that I was treating them as identical blades – mounting them on identical snaths and setting the hafting angle the same for both blades. We also found that Tony’s 75cm Falci performed much better than my 75cm Falci – the same length blade from the same batch – so there was also obviously something going on with my blade.
The really big problem turned out to be the twist of the tang on my Falci blade – it needed a lot of adjustment. I’d spoken to Peter Vido about the variation in the Falci blades and he’d given me some pointers about sorting out any problems, but I have to confess that I figured the main impact these changes would have would be on ergonomics and comfort – not so much on performance.
But when I addressed the tang twist, the difference in performance was amazing – which is why we adjust the tang angles on the blades we ship, if they don’t fall within certain parameters.
More experimentation is good
So why all this reflection? Well, we’ve recently been trying some blades of another origin (more on that another day) and comparing them to the Falci and the Fux. And it got me experimenting again, and the results have surprised me again. Conventional wisdom has it that for a 75cm blade, a straight-edge placed along the face of the tang would meet the blade somewhere between halfway along the blade and three quarters of the way along the blade, as pictured below:
On a 90cm blade, the tang has more twist – it should ‘point’ somewhere between one quarter and one half of the way along the blade:
Here’s a photo of a 75cm blade with a ‘standard’ tang twist applied:
With very short blades the twist is less of an issue as they’re often used for off-ground mowing and the shorter length makes the point less inclined to dig in.
What I did in the most recent round of experimentation was to take things to an extreme. I wedged the blades so that the twist was effectively the same as a very twisted tang, and I closed the hafting angle – a lot. So while conventional wisdom would suggest a three-finger hafting angle would be a good starting point for a 75cm blade, I more than doubled it. And the results surprised me. I expected to get virtually no depth of cut at all due to the very closed hafting angle – and indeed it felt like I wasn’t cutting grass – but I was cutting grass, and quite nicely thank you very much. I called Tony over and asked him to try it, and his comment was, “it’s like the grass isn’t even there!”
I played with it some more and found that, for me at least, the extra tang twist made more of a difference to the overall performance than the extra hafting angle. I’m so convinced by the results of this experimentation that I broke out the oxy torch and set a couple of my blades this way, permanently: my 75cm now has a tang twist that conventional wisdom would have it as far too steep: I have it twisted steeper than many 90cm blades.
I also added some extra twist to my 90, and in testing I did actually take it even further, but found that beyond a certain point the twist starts to affect how you hold the snath – because the tip is so far off the ground that you need to roll the grips around over the snath to get the point anywhere near mowing range, which has knock-on effects in itself.
Tony, meanwhile, felt that the extra hafting angle was still worth pursuing – any loss of ‘bite’ (or depth of cut) did seem to be made up by the ease of mowing afforded by the closure.
So, a photo first, and then some wild speculation about what’s going on here.
What these adjustments do, practically, is lift the point off the ground. You can roughly quantify how much lift (relatively speaking) you’re getting in the point by looking along the flat edge of the top face of the snath with the blade fitted up:
So what’s happening?
I heard of a visiting Canadian chopping team who sank their axes into our tough Australian timber and wondered what the hell they’d struck. Anyone who’s worked with some of our timbers like Red Gum or Gidgee would more than understand that experience. I had also heard people speak of our ‘tough grasses’, and wondered whether there was really anything to the claim. As an excuse for an unsuccessful mowing experience, it always struck me as pretty flimsy; there have been enough times when I’ve taken to mowing what seemed to be an impenetrable barrier, only to find that if I change one thing, or a couple of things, the impenetrable is swept away cleanly. The things to change can include varying angles on your blade setup, the edge preparation, grip adjustment, and direction of approach to the target… pretty much anything. If I’ve learnt one thing about scythe mowing, it’s that there’s always more to learn, and a wider range of experience in different mowing conditions helps you identify what’s going wrong.
But in talking to Tony, he pointed out (he’s a botanist) that it’s long been suggested (since the 1960s) that our low phosphorous soils cause sclerophylly – the hardening of vegetation that gives rise to our ‘sclerophyll forests’. In hunting this down, I’ve confirmed that the hypothesis now seems to be regarded as fact, but I haven’t been able to find any evidence for or against a hypothesis that such a response could be manifest within a generation. That is, we know that our native grasses are tougher – and presumably they’ve evolved that way over innumerable generations – but I haven’t come across anything to suggest or discredit a notion that a hardening of vegetation would occur to an individual plant which has recently been phosphorous-deprived – e.g. an introduced species sown into our soil. In scientific terms I guess the question would be whether low phosphorous is solely a selection pressure, or whether low phosphorous can actually produce a sclerophylly response in an individual plant. I’m sure someone knows the answer, but with a bit of casual browsing on the interwebs, I haven’t found it. I might make a more concerted effort at a later stage.
In the meantime, I thought I’d take the camera out and film some cocksfoot grass, and get some comments from mowers in other climes on whether they have grasses of equivalent presentation. Out to the left here is a photo of me standing next to a clump of rank cocksfoot. As far as mowing grass goes, this is about as tough as it gets here in my neck of the woods.
I asked my daughter to film me while I tackled that very clump:
Cocksfoot, of course, is not a native Australian grass, and if there are any European or Mediterranean readers out there who can comment on how these grasses present in their natural surrounds, we’d be interested to hear.
And we do also have paddocks of lush green, leafy grass and clover, and some of that lush grass is cocksfoot – it only goes clumpy like this when it has “inadequate” grazing. And when it gets to this stage, even tractor-mounted mowers have trouble getting it back to normal length.
Okay, but what’s that got to do with your crazy tang twist?
Well, I’m beginning to suspect, everything. The Falci blades are quite flexible along their length. You can hold the beard flat against a surface such that the point sits quite high in the air, and then fairly easily push that point down onto the same surface. It may tend to twist along the rib a bit, but it will still go down. So I think what may be happening is that the hard stems are collectively putting up enough resistance to have that effect of pulling the tip down, which makes the tip tend to dig in, and give a rougher ride all round. Whereas on a lawn where the resistance offered by the grass is negligible, you can get away with a tang twist that will give you all kinds of grief in a paddock.
But I’m really just speculating. And it should be stressed that, as with most things on scythe setup, “conventional wisdom” is just a starting point. So my crazy tang twist may not actually be so crazy after all – again, we’d love to hear comments from others who have experimented.
I’d encourage others to try the same – wedge your blades to lift the tip and see what happens. Ideally you should use a full snath-width wedge that distributes the pressure of the attachment ring pressing the tang onto the snath as evenly as possible, so as to not damage the end of the snath. A wedge in this shape is ideal:
And inserted like this:
We’d love to hear how it goes.